棉花晋A细胞质雄性不育系小孢子发生的显微和超微结构观察

The Microstructural and Ultrastruc-tural Study on Microsporogenesis of Cytoplasmic Male-sterile Cotton Line Jin A

研究了棉花晋 A细胞质雄性不育系的细胞学特征。结果表明 ,1晋 A不育系雄性败育的主要时期是在造孢细胞增殖——小孢子母细胞形成时期。大部分小孢子母细胞在形成过程中退化解体 ;少数小孢子母细胞能进一步发育并开始减数分裂 ,但都仅停留在减数分裂前期 ,该不育系绒毡层提早解体与小孢子母细胞解体有关。 2小孢子母细胞和绒毡层细胞中的线粒体异常 ,对晋 A不育系小孢子败育有直接的影响。线粒体异常表现的特征为 :线粒体肿胀破裂 ,内嵴溶解。

This study was conducted on the male sterile cotton line Jin A in mo rphological characters.The results showed that: (1) The auxocyte abortion of Ji n A took place at the stage of sporogenous cell division. In most cases,the spor ogenous tissues collapsed and coalesced during the premiotic stage of developmen t,while occasionally a few microspore mother cells formed and meiosis progressed in some locules. However, these cells degenerated during the early stages of pr ophase Ⅰ.The collapse of the tapetum was responsible for the abortion of micros por mother cells. (2) The abnormal mitochondrium in microspore mother cells and tapetume cells had directly effects on abortion of MMCs.The abnormal characteris tics of mitochondrium are inflation and splitting of mitochondrium, melt and dis appearance of cristae.